胃肠道神经鞘瘤与胃肠间质瘤CT征象的比较研究

Comparative study on computed tomography features of gastrointestinal schwannomas and gastrointestinal stromal tumors

目的比较胃肠道神经鞘瘤（GIS）与胃肠间质瘤（GIST）的cT征象，寻找有助于提高二者鉴别诊断水平的CT特征。方法回顾性收集2000年1月至2014年7月于中山大学附属第一医院放射科行CT检查并经术后病理证实的50例GIST和15例GIS患者的临床及影像学资料。比较两种肿瘤的cT征象，对两种肿瘤cT征象间差异有统计学意义的CT征象绘制ROC曲线，并计算曲线下面积（AUC）及鉴别诊断的敏感性和特异性。结果GIS与GIST的肿瘤大小、形状、是否囊变、肿瘤周围淋巴结、肿瘤血管、强化方式、强化程度、绝对CT值和标准化CT值比较差异均有统计学意义（均P〈0．05）。在各种CT征象中，肿块大小、囊变、肿瘤周围淋巴结、强化方式及动脉期标准化cT值（Sa）的鉴别诊断能力较好，AUC均大于0．7，其中肿瘤大小的敏感性最高，为90％；而囊变和sa的特异性最高，为87％。结论GIS更倾向于是一种较均质的肿瘤，呈轻中度均匀强化，肿瘤周围多有明显强化的肿大淋巴结；而GIST具备恶性肿瘤的特征，如血供相对丰富，体积较大，易出现坏死和囊变等。cT征象中的囊变和Sa对GIST与GIS有较好的鉴别诊断价值。

Objective To compare the CT image of gastrointestinal schwannomas （GIS） and gastrointestinal stromal tumors （GIST）, and to find the CT features to be helpful for differentiation of GIS from GIST. Methods Clinical and iconography data of 15 GIS patients and 50 GIST patients who underwent stomach CT scan with postoperatively confirmed histopathology between January 2000 and July 2014 in our department were collected retrospectively. CT findings of these two tumors were compared. Then the ROC curve was drawn based on the significant CT findings and area under the curve （AUC） was calculated to assess the sensibility and specificity for the differential diagnosis of GIS and GIST. Result CT findings, such as the tumor size, shape, cystic change, perilesional lymph nodes, vessel seeding, enhancement pattern and degree, absolute and standardized CT value were significantly different between GIS and GIST （all P〈0.05）. Among the CT findings, tumor size, cystic change, perilesional lymph nodes, enhancement pattern and arterial phase standardized CT value （Sa） were better differential than others （all AUC〉0.7）. Tumor size showed the highest sensibility （90%）, and cystic change and Sa showed the highest specificity （87%）. Conclusions GIS seems to show a homogeneous tumor more frequently, presenting light and moderate enhancement pattern and obvious enhancement of perilesional lymph nodes, while GIST seems to reveal malignant features, such as abundant blood supply, larger volume, frequent necrosis and cystic change. Cystic change and Sa value possess the better differential ability in diagnosis of these two tumors.